GeometrySelectionUtil: add FindByTopologyID function, to search a Selection for selected element with matching TopologyID but ignoring GeometryID. Update FGeometryScriptMeshSelection::CombineSelectionInPlace() to use this, as it was not properly combining Polygroup selections.
#rb none
#preflight 630501435a5d4e462428af90
[CL 21516930 by Ryan Schmidt in ue5-main branch]